1. Field of the Invention
The present invention relates to a photographic camera having an exposure control unit and a focus control unit each providing a plurality of control modes and the ability to switch over between the control modes. More particularly, the exposure control unit provides a programmed exposure control mode where an aperture value and a shutter speed are automatically set in accordance with a detection result of a light metering sensor and with a predetermined program and a manual exposure control mode where at least either the aperture value and the shutter speed value is manually set. The focus control unit provides an autofocus mode where focusing is effected automatically based on a detection result of a focus detection sensor and a manual focus mode where a focusing is effected manually.
2. Description of the Related Arts
A commercially available photographic camera of the above-noted type permits a user to freely select the one mode from the exposure control modes and to freely select the one mode from the focus control modes by operating independent switches.
Further, in the manual exposure control mode, at least three exposure modes are available for the user: an aperture-priority mode where the exposure control unit, which is incorporated in the camera body, automatically sets a shutter speed with the user's presetting of an aperture value; a shutter-priority mode where the exposure control unit automatically sets an aperture value with the user's presetting of a shutter speed, and a full manual mode where both an aperture value and a shutter speed are freely set by the user himself. These manual exposure modes are useful for emphasizing the contrast of the photographic object, enlarging an in-focus range through utilization of the depth of field, or for freezing an action of a fast moving object such as in a sports photography. While experienced users may intentionally use these manual exposure setting modes in order to obtain a desired effect, these modes are rarely used by inexperienced users.
Similarly, the manual focus mode is apt to be used only by experienced users because of, e.g. the troublesomeness of the focusing operation.
Accordingly, this type of automatic camera permits switchovers in the exposure control mode and the focus control mode between the automatic mode and the manual mode so that an inexperienced user also may make full use of the camera. Naturally, such an inexperienced user tends to use the programmed exposure control mode for the exposure setting and the autofocus mode for the focus setting. However, if the user switches over to the manual exposure mode and to the manual focus mode when he wishes for a particular photographic mode and then wishes to reset the modes back to the programmed exposure control mode and to the autofocus mode after the particular photograph, he must usually operate two different switches for the mode resetting operations.
Moreover, if the cameral is of the lens type, the above-described exposure and focus control modes switchover operations entail further inconveniences to be described next.
As described above, such a camera permits selective use of various types of exchange lenses having different focal lengths, aperture values and so on. Some of such exchange lenses, e.g., a macro lens, require manual settings of aperture value and shutter speed for best results. Further, the user may want to manually set the camera for the other types of exchange lenses as well to obtain some special effects described hereinbefore. Then, when the photography has taken place by such manual setting mode and the lenses are again exchanged for a next photography by the automatic modes, conventionally the user must operate the manual operational elements for the mode switchover operations.
Especially, if the photographs using the different lenses take place with a considerable time interval therebetween or if a different user uses the same camera in the next photography, the user will often forget or be uninformed of the modes being currently set at the manual modes. Then, since the program setting mode is easier and more commonly used in this type of camera, the user mistakenly takes it for granted that the camera is set at the program mode and just proceeds to take the photograph without doing focusing or shutter speed and aperture value setting operations. Naturally, this photograph will turn out unsatisfactory because of inapropriate focusing and/or exposure. That is, the user will waste the film and fail to capture the precious moment.